Will Wilkinson: Is a Non-Ideological Political Philosophy Possible?:
It's mostly personal epistemic virtue, but the content of belief helps too. I think a moderate general Pyrrhonism plus conceptually savvy empiricism plus pluralism plus a socially deliberative/procedural bent (not just democratic but also scientific) adds up to something close to non-ideological--as close one is likely to get, at any rate.
I stopped calling myself a libertarian in part because I thought my many marginal disagreements added up to something really substantive and categorical. Mostly, though, because ideological self-definition inwardly encourages a spirit of community and camaraderie and partisanship that is one of the blessings of life, but which also makes true philosophy next to impossible. I struggle daily with the possibility that I have made the wrong decision, and that belonging, even on the basis of shared error, is more important than truth. Where my label was, there is a scar.